Indigoid vat dyestuffs



-T grey shades.

Patented July 28, 1931 "UNITED STATES PATENT OFFICE 1 NORBERT STEIGER, or FRANKFURT-ON-THE-MAIN, G RMANY, *ASSIGNOETO GENERAL. N. Y.Y,VA CORPORATION on DELAWARE ANILIN E WORKS, INC, OF NEW YORK,

IN D'IGOID VAT DYESTUFFS No Drawing. Application filed April 11, 1930, Serial No. 443,621, and in Germany April 22, 1929.

My present invention relates to new asymmetrical indigoid vat dyestuffs WhlCll corre-- spond to the general formula:

(wherein X means chlorine or bromine).

These dyestuffs dye animal and vegetable fibres grey shades and are very suitable for printing purposes. The dyeings and printings thus produced are distinguished by very good properties of fastness. Even light dyeings on wool show an excellent fastness to light and exposure.

In order to further illustrate my invention the following examples are given, the

parts being by weight and all temperatures in Centigrade degrees. I wish it however to be understood that I am not limitedto the particular conditions nor to the specific products mentioned therein Ewample 1 It represents a violettish black powder, soluble in sulfuric acid to a green solution, forming a yellow vat, yielding on cotton by printing and dyeing grey shades of a good fastness. Also .wool is dyed from the vat Even light dyeings on wool nearly the same digoid vat dyestuffs show an excellent fastness to light and ex posure.

6-methyl-3-hydroxy-thionaphthene used as starting material may be produced for instance as follows:

l-methyl 4 -amino 5 mercapto-benzene (prepared e; g. by subjecting dehydro-thiotoluidine to the action of melting alkali) is condensed in the known manner with monochloro-aeetic acid and the l-methyl-4-aminobenzene-5-thioglycollie acid thus formed is converted into 6-methyl-3-hydroxythio-naphthene in the usual way.

Example 2 11.5 parts of 5-bromo-isatine are heated for 2 hours to 100 pentaohloride and 120 parts of ohloro-benzene. The solution of the a-ChlOIldO thus produced is mixed while stirring at 8085 with a solution of 8.3 parts of 6-methyl-3- hydroxy-thionaphthene in 120 parts of chloro-benzene. After stirring for about 1 hour the formed dyestufi is filtered ofi'. Itcorresponds'to the formula:

It represents a violettish black powder of properties as the product of Example 1.

I elaim:- 1. As new compounds the asymmetrical incorresponding to the general formula:

Ba 8 N (wherein X means chlorine 'or bromine), which compounds are violettish black ders dyeing and printingv Wool and cotton with 11.5 parts of phosphorus pow-.

grey shades of a very good fastness, especially to light and exposure.

' 2. As a new compound the asymmetrical indigoid vat dyestufi corresponding to the formula: V

-oo oo 01 the S 10 i which compound is a violettish black powder dyeing and printing wool and cotton grey shades of a very good fastness, especially tov light ancl exposure. r 7

15 Intestimony WhereoL IafliX my si at re.

7 V NORBERT'STEIGER. 

